Switch box with plug-in cable connection



Feb. 20, 1934. E. G. K. ANDERSON SWITCH BOX WITH PLUG-IN CABLE CONNECTION Filed May 27, 1932 I I. mi

Patented Feb. 20, 1934 SWITCH BOX WITH CONNE PLUG 4N CABLE CTION Ernst G. K. Anderson, Evanston, Ill., assignor to Appleton Electric Company, a corporation of Illinois Application May 21. 1932. Serial No. 613.821

The object of the present invention is to make it impossible to disconnect a cable plugged into a switch box except while the switch is open, whereby all arcing that occurs will take place I within the box and not externally.

The various featuresof novelty whereby my invention is characterized will hereinafter be pointed out with particularity in the claims; but, for a full understanding of my invention and of its objects and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawing,

wherein:

Figure 1 is a front elevation of a box embodying the present invention, showing two plug connections, and the screw and washer securing in place one of the holding plates for the plugs being omitted; Fig. 2 is a view of the box, partly in side elevation and partly in section; Fig. 3 is a front elevation of a fragment of the box with the cover removed; Fig. 4 is a section on line 44 of Fig. 2; Fig. 5 is a view similar to Fig. 4 showing the parts in the positions which they occupy when the switch is open, whereas in Fig. 4 the parts are in the positions assumed by them when the switch is closed; Fig. 6 is a section on line 6-6 of Fig. 1; and Fig. 7 is a view of the inner side of the removable top for the box, only a fragment being shown.

Referring to the drawing, 1 represents a box containing a switch, both being of any usual or suitable construction. The box has a detachable side which is in the form of a casting 2 mounted in a box-like cover 3. The switch is provided with an arm or lever 4 projecting into a chamber 5 in the inner side of the block or body 2; the free end of this lever being preferably in the form of a fork 6. The actuator for the switch is a rod .7 extending into the detachable section of the box from above and passing through the chamber 5. At some distance from its inner end the actuator is provided with a section 8 of reduced diameter which is straddled by the fork or jaw 6 on the switch lever. The portions of the actuating rod of full diameter at the ends of the reduced section produce shoulders that will engage with the switch lever when the rod is moved up and down and cause the switch to be opened and closed. In the arrangement shown, the switch is assumed to be closed when the actuator is down, as shown in Fig. 2.

In thedetachable wall of the box are two sockets 9, 9 of any usual or suitable construction adapted to cooperate with complementary plugs 10, 10 to connect cables A and B to the switch.

In accordance with my invention I provide means to prevent the plugs from being separated from the sockets except when the switch is open. so that the circuit must be broken at the switch and any arcing that occurs at the time of interrupting the circuit will take place within the sealed box. In tharrangement shown, the looking or safety devices are in the form of wings 11 and 12 each comprising a substantially circular part and a radial extension. These wings are supported on the outer ends of two shafts 13 and 14 extending entirely through the members 2 and 3 and through a-post or pedestal 15 forming part of the box member 2 and projecting from that member outwardly through the cover 3. A plane containing the axes of the shafts 13 and 14 is parallel with a plane containing the central axes of the sockets. Furthermore, the shafts are spaced 8. short distance apart, one on each side of the longitudinal center of the box as are the sockets. The radial extensions of the wings 11 and 12 rest directly on top of the post or pedestal l5 and also on the upper ends of the body portions of the shafts 13 and 14. These shafts are provided at their upper ends with small central bosses or lugs rectangular in cross section, as indicated at 16; the locking wings having openings into which these bosses or lugs fit. The wings are fastened to the shafts by means of screws 1'7 that extend down through the wings and into the upper ends of the shafts; suitable washers 18 being placed between the under sides of the heads of the screws and the outer faces of the wings.

The parts are so proportioned that in one angular position of each of the shafts the circular free end of the corresponding wing lies directly above one of the sockets, although spaced apart therefrom whereas, in another angular position of each of the shafts, the wings have been swung laterally away from the sockets so as to leave the space above or outside of the latter unobstructed. The wings themselves may act as cooperating stops to limit their movements between these two positions. Thus, in Fig. 1, the wings are shown as overlying the sockets, and it will be seen that the radial extensions thereof are in edge to edge contact. Each wing is shown as being provided along the edge farthest from the other wing with an inwardly-turned flange 19. These flanges terminate at such points at the supported ends of the wings that they will come in contact with each other when the wings are swung apart and arrest such swinging movements as soon as the wings have been carried laterally beyond the sockets.

When the wings are in the positions shown in Figs. 1 and 2, overlying the plugs that have been engaged with the sockets, these plugs cannot be withdrawn until the wings are swung out of the way. In order that the wings shall not interfere with the cables by which the plugs are carried, I cut out of the circular portion cf each wing a comparatively wide section extending from the center to the periphery at the inner side or edge of the wing; thus forming what may be termed a wide, deep notch 20 in each wing that will permit the wings to be swung back and forth without coming in contact with the cables.-

The wings are swung in one direction by means of springs and in the opposite direction by means of the switch actuator. I prefer that the springs operate in a manner to swing the wings into their idle positions, and this is the arrangement that I have illustrated. The spring means for this purpose may consist of a single piece of spring wire coiled at its ends into two separate helical springs 21 and 22, each surrounding the lower end of one of the shafts; the free ends of the wires being inserted in grooves 23 in the inner or under ends of the shafts. The two springs are therefore tortion springs which I place under an initial tension sufficient to swing the wings apart whenever they are left free to do so.

.The long axis of the actuating rod 7 lies midway between the centers of the sockets and midway between the long axes of the shafts 13 and 14 so that, as the actuating rod is moved back and forth, its path extends between the two shafts. The distance between the two shafts, or at least those portions thereof opposite the switch actuator, is considerably less than the diameter of the actuator. However, the inner sides of the shafts are cut away in line with the actuator to make room for the latter between the shafts when they are in predetermined angular positions relative to each other. The mutilation of the shafts is such that they present to the actuating rod when the shafts are in the positions which they occupy when the wings are spread apart, as illustrated in Fig. 5, oppositely inclined faces 24, 24 which, at their inner near ends, are spaced apart a distance less than the diameter of the rod. In Fig. 5,-the actuator is shown in the position which it occupies when the switch is open, the advance end touching the inclined faces 24 on the shafts. when the actuator is pushed in, it acts on these inclined faces 24 to move them out of the way and thus turn the shafts so as to permit the actuator to pass between them into the position illustrated in Fig. 4 in closing the switch. The inclined faces on the shafts are conveniently produced by placing the two shafts in the relative positions which they will later occupy when the safety wings are overlying the sockets, and then drilling a hole through the same coaxial with and of the same diameter as the actuating rod; this hole lying partly in one shaft and partly in the other, as best shown in Fig. 6.

It will be seen that, when the actuator is fully Y connected from the sockets until the actuator is withdrawn into the podtion illustrated in Pig. 5 and opens the switch.

The construction shown is one in which the interlock will be effective if the cover plate 2 is turned end for: end, unless the switch likewise be turned. I have, therefore, provided an interlock between the switch and the cover plate so that the detachable wall carrying the switch actuator can be applied to the box only in a manner properly to locate the actuator relatively to the switch handle. To this end I have provided one of the plates or brackets 25 by which the switch is secured in the box with tongues 26, 26 projecting outwardly at right angles thereto. These tongues will enter a hole 27 in the detachable wall of the box when the latter is properly applied; but will strike a solid part of that wall if it be attempted to apply the latter turned end to end from the position that it occupies relatively to the switch in Fig. 2.

The operation probably has been made clear in the foregoing description. However. it may be said that normally, when the switch-actuating rod is pulled out and the switch is open, the

springs hold the wings 11 and 12 spread apart so that the sockets in the box remain uncovered. At this time the plugs may be inserted or removed, at will. when the actuator is pushed in, closing the switch, the wings are swung together so as to overlie the sockets. No plug can now be engaged with the sockets or, if already engaged, cannot be disengaged; but the switch mustiirstbeopenedtopermitthewingsto spread apart.

WhileI have illustrated and described with particularity only a single preferred form of my invention, I do not desire to be limited to the exact structural details thus illustrated and described; but intend to cover all forms and arrangements which come within the definitions of my invention constituting the appended claims.

I claim:

1. The combination with a box containing a switch and having a socket to receive a plug on a cable or the like, of a locking member pivoted to the box beside the socket and adapted to be swung over a plug in the socket and lock the plug against withdrawal, a spring tending constantly to swing said member into an idle position clear of said socket, a switch actuator, and cooperating elements on said member and said actuator including a cam face to cause said member to be swimg into its locking position when the actuator is moved to close the switch.

2. The combination with a switch box containing a switch, having a removable wall, and provided with a socket to receive a plug on a cable or the like, of a slidable switch-actuating rod mounted in said wall for lengthwise sliding movements in the plane of the said wall, a rotatable shaft mounted in and projecting from said wall at right angles thereto, a member fixed upon the outer end of said shaft and adapted to overlie a plug in said socket and lock it against withdrawal in one angular position of the shaft and to lie at the side of the socket in a second angular position of the shaft, a spring tending constantly to hold the shaft in the said second angular position, and cooperating elements on the actuating rod and the shaft to cause the shaft to be turned into the first-mentioned angular position when the rod is moved in the direction to close the switch.

3. The combination with a switch box containing a switch and having two adjacent sockets to A", .1 IA I) receive plugs on cables or the like of two rotatable shafts spaced a short distance apart and rising from the box beside the sockets, wings fixed to the outer ends of the shafts and each adapted to overlie a plug in one of the sockets in one angular position of its shaft and to leave the space outwardly from the socket clear in a second angular position of the shaft, springs tending constantly to hold the shafts in the second of said angular positions, said shafts having inclined faces on the sides nearest each other, and a switch actuator movable into and out of the space between said inclined faces and having a part cooperating with said faces to turnthe shafts into the first of the aforesaid angular positions when the actuator is moved to close the switch.

4. The combination with a switch box having a removable wall, a socket to receive a plug on a cable or the like in said wall. and a switch, of a post projecting from said wall beside said socket, a shaft extending through the length of the post, a member fixed to the outerend of the shaft and adapted to overlie said socket when the shaft is in one angular position, a spring on the inner end of the shaft tending constantly to hold the shaft in a second angular position and said member clear of said socket, a sliding actuator for said switch mounted in said wall for movements at right angles to said shaft, and a part on said shaft in position to be engaged by said actuator when the actuator is moved to close the switch to cause the shaft to be turned into its first mentioned position.

5. The combination with a switch box containing a switch and having a socket to receive a plug on a cable or the like, of actuating means for the switch including a reciprocable part, a shaft rotatably mounted on the box beside the socket and extending parallel with the axis of the socket and at right angles to the path of travel of said reciprocable part, said shaft and said reciprocable part having cooperable engaging faces to cause said shaft to be turned 'into one angular position when the switch is closed, and means on said shaft in position to be swung over said socket when the shaft is brought into its first angular position and to be carried clear of the socket when the shaft is in its second angular position.

6. The combination with a switch box containing a switch and having a socket to receive a plug on a cable or the like, of actuating means for the switch including a reciprocable part, a shaft r0- tatably mounted on the box beside the socket and extending parallel with the axis of the socket and at right angles to the path of travel of said reciprocable part, said shaft and said reciprocable part having cooperable engaging faces to cause said shaft to be turned into one angular position when the switch is closed, means on said shaft in position to be swung over said socket when the shaft is brought into its first angular position and to be carried clear of the socket when the shaft is in its second angular position, and a spring tending constantly to move said shaft into its second angular position.

ERNST G. K. ANDERSON. 

